Suemin Chi
November 30th, 2013
The Genetics Disease: Galactosemia There are many genetic diseases out there today, but one that caught my attention was Galactosemia. Galactosemia is a genetic disorder that affects how the body processes the simple sugar, galactose. There are three types of Galactosemia; Classic Galactosemia, Galactosemia Type II, and Galactosemia Type III. All three types are inherited in an autosomal recessive pattern but the most common is the classic Galactosemia. According to the Genetics Home Reference, it states, “Classic Galactosemia occurs in 1 in 30,000 to 60,000 newborns, Galactosemia type II and type III are less common; type II probably affects fewer than 1 in 100,000 newborns and type III appears to be very rare.” This disorder is rare but if affected with it, can show symptoms that range from mild to very severe if not controlled.
Those who are affected with classic galactosemia lack the enzyme Galactose 1-phosphate; (GALT), galactosemia type II has a mutation in the GALKI gene and in type III, the GALE gene. Galactose is one of the products formed from lactose when absorbed into the body. In an unaffected person, GALT will bind to galactose, which later converts to glucose and then used for energy. In an affected person, there is no GALT, so the build up of galactose will cause toxic affects on the organs. This is a very dangerous disorder one can have, but it is especially dangerous to newborns because they will not be able to drink any milk that contains lactose, which unfortunately includes breast milk.
Newborns with galactosemia are not easily detected since they may look healthy at birth but symptoms start showing after their first couple milk feedings. Some signs and symptoms of galactosemia in newborns are diarrhea, weight loss, jaundice, vomiting, convulsions, irritability, lethargy and poor feeding. According to the article, Role of Diet Therapy in Management of Hereditary Metabolic Diseases it states, “In the newborn period failure to thrive and vomiting, usually beginning within a few days of milk ingestion, are the common clinical presentations”. The only way to test if ones newborn has galactosemia is through a very simple blood test. According to the information stated on the website, Learn.Genetics, “In most states, babies are tested for galactosemia at birth. Using a tiny blood sample taken from the baby’s heel, the test checks for low levels of the GALT enzyme”. Although there is no cure for galactosemia, it can be controlled and the severity of the problems can be decreased with a galactose-restricted diet.
A galactose-restricted diet is a life-long diet and getting off of it can have very severe consequences. The most important thing is that people with this disease have to stay clear from milk and other dairy products i.e., breast milk, cheese, ice cream, butter, yogurt and cream. Children and adults are allowed to eat most proteins like beef, poultry and eggs, as well as bread, fruits and vegetables but for newborns, they can only get their nourishment through soy formulas that do not contain any lactose.
Following the restricted diet is very important because a lot of organs are affected. According to Role of Diet Therapy in Management of Hereditary Metabolic Diseases, “The galactose free diet can reverse jaundice, liver disease, renal tubular dysfunction, and cataracts”. The restricted diet helps to prevent damages and lessen the problems that arise with this disease especially if it is started as soon as possible.
Organs that are affected from this disease are the brain, eyes, liver and kidneys. Since galactose cannot be broken down, it starts to build up in the body and it causes these organs to show complications due to the high toxic levels of Galactose 1-phosphate. Serious complications that occur are cataract in the eyes, kidney failure, enlarged liver, poor growth, delayed speech, mental retardation, tremors and even uncontrollable motor functions.
One of the arising questions people with galactosemic children are whether or not their child will grow normally like other children. A newborn that starts on a soy formula without lactose, and then continuing on with the restricted diet as they age, can have a normal physical growth but this can only be achieved if the diet is followed. The article, An Updated Review of the Long-Term Neurological Effects of Galactosemia states, “Growth is generally delayed in most patients with galactosemia, but final height-for-age is not significantly less than the general population, although females may be more likely to have short stature”. Normal physical growth is one complication but it is not as severe as the others.
One of the more severe problems that can occur and be reduced/resolved by following the strict lactose free diet is Cataracts. Cataracts are the clouding of the eye lens and according to the article, An Updated Review of the Long-Term Neurological Effects of Galactosemia, it states, “Cataracts have been reported in up to 30% of patients with galactosemia, and they usually resolved with galactose restriction”. The article also states that ovarian failure can be a result from not controlling the disease. An Updated Review of the Long-Term Neurological Effects of Galactosemia states, “Hypergonadotropic hypogonadism is common in females with galactosemia but has not been reported in males. The spectrum varies from severe primary ovarian failure requiring hormone support in order to achieve secondary sexual characteristics to premature menopause”. Having ovarian failure complicates women who want to have children since premature menopause can take place or women who don’t want to have kids can get pregnant due to their irregular or occasional periods. Restoring estrogen levels in women who have ovarian failure can help prevent any complication that can turn up.
It cannot be stressed enough how important it is to stay on track of the restricted diet because there are no other treatments for this disorder and it is a life-long threat. Galactosemia is not a disease that one can just catch like a cold or flu. It is an autosomal recessive trait and that means that two copies of the mutated gene must to be present in order for the disease to develop. Parents who have a child with galactosemia had to have been carriers; each parent had one gene for galactosemia and one gene for non-galactosemia. Both parents do not show signs or symptoms of galactosemia but when they have kids, they either pass on their galactosemia gene or their other gene.
If a Punnett square were to be done for parents who were both carriers, the results would show a 1:2:1 ratio. The parents would have a 1/4th chance that their kid would not have galactosemia, 2/4th chance of having a baby that is a carrier to galactosemia and a 1/4th chance of their kid having galactosemia. If parents know they are both carriers of galactosemia, it may be beneficial to seek a genetic counselor or a doctor who has knowledge on galactosemia for any questions or advice.
For parents with a family history of galactosemia or who are both carriers of the gene, can benefit from seeking a genetic counselor prior to having children because they can help answer any questions or concerns. The disadvantage of seeking a genetic counselor is that it can be expensive and so it may not be for everyone, but that should not stop parents from looking for information. There are many online support and educational resources available for people and they can be just as helpful as going to see a genetic counselor. For example, the National Center for Biotechnology Information has a page called Resources for Galactosemia. On this page, it has different categories for different questions or situations for the disease and directs you to its appropriate sites/links. Parents who carry the galactosemia gene, or even have a slight chance of carrying the galactosemia gene, should seek out to gather as much information they can on the disease. It is very helpful to know about the disorder and what needs to be done in order to control and reduce the affects it has on the body, since it is not curable and is a life-long threat if not managed appropriately.

Works Sited
An Updated Review of the Long-Term Neurological Effects of Galactosemia
Pediatric Neurology, Volume 33, Issue 3, September 2005, Pages 153-161
Keith R. Ridel, Nancy D. Leslie, Donald L. Gilbert
"GALACTOSEMIA." Galactosemia. The University of Utah. Web.
29 Nov. 2013. <http://learn.genetics.utah.edu/content/disorders/whataregd/galactosemia/>.
"Galactosemia." Genetics Home Reference. 25 Nov. 2013. Web. 28
Nov. 2013 <http://ghr.nlm.nih.gov/condition=galactosemia>
“Galactosemia.” The New York Times, Health Guide. Web. 28 Nov. 2013 <http://www.nytimes.com/health/guides/disease/galactosemia/overview.html>
"Resources for Galactosemia." NCBI. U.S. National Library of Medicine,
n.d. Web. 28 Nov. 2013.
<http://www.ncbi.nlm.nih.gov/sites/ga?disorder=galactosemia>.
Role of diet therapy in management of hereditary metabolic diseases
Nutrition Research, Volume 18, Issue 2, February 1998, Pages 391-402
C. Prasad, L. Dalton, H. Levy